MALVACEAE 



209 



The diameter of the pollen-grains in M. rotundifolia is about 100 /*, in M. 

 neglecta about 112 /a, and in M. sylvestris as much as 144 p. In all these species 

 they are closely beset with long spines (Warnstorf). 



Visitors. Herm. Miiller observed the following. 



A. Hymenoptera. Apidae: 1. Anthophora quadrimaculata F. J ; 2. Apis 

 mellifica L. !jf; 3. Bombus agrorum F. $j; 4. Halictus morio F. $; 5. H. tetrazonius 

 Kl. 5 ; all skg. B. Hemiptera. 5. Pyrrhocoris aptera L., skg. 



MacLeod saw Apis, 2 sp. of Halictus, Syritta, and a Muscid in Flanders (Bot. 

 Jaarb. Dodonaea, Ghent, vi, 1894, p. 229), and an Apid in the Pyrenees. 



518. M. neglecta With. (Knuth, ' Bl. u. Insekt. a. d. nordfr. Ins.,' pp. 48, 

 152.) The flower mechanism of this species is intermediate between those of M. 

 sylvestris and M. rotundifolia. Here again, at the beginning of anthesis, the pyramid of 

 anthers borne on the united filaments completely encloses the still completely immature 

 stigmatic branches. After dehiscence the upper free ends of the filaments bend 

 downwards, so as to uncover the previously enclosed stigmas. These now spread 

 out in all directions, curving backwards so far that the papillae on their inner sides 



Fig. 63. Malva neglecta, With. (Magnified about 5 times, after removal of calyx and corolla. From 

 nature.) (1) Bud condition : column of stamens with unripe anthers. (2) Early male condition : column 

 of stamens with dehiscing anthers surrounding the immature stigmas. (3) Later male condition : the 

 styles project somewhat from the column of stamens, otherwise as before. (4) Early hermaphrodite 

 condition (adapted to cross-pollination) : the receptive stigmas project above the stamens (which are 

 directed downwards, but still covered with pollen) and spread out like a star in the entrance to the flower. 

 (5) Later hermaphrodite condition (adapted to automatic self-pollination) : the stigmas have rolled them- 

 selves spirally round the anthers, which are still covered with pollen. a, stamens; s, stigmas; 

 n, annular nectary ring. 



project freely, and occupy the place where the anthers were at first situated. Insects 

 coming from a flower in the first stage to one in the second stage must consequently 

 effect cross-pollination. Towards the end of anthesis, the stigmatic branches curve 

 downwards so far as to come into contact with the stamens which are still covered 

 with pollen to some extent ; and thus automatic self-pollination takes place, if insect- 

 visits have failed. 



Visitors. In the island of Fohr I only observed the honey-bee, skg. and 

 po-cltg. 



519. M. mauritiana L. Kirchner ('Flora v. Stuttgart/ p. 332) states that 

 the flower mechanism of this species agrees with that of M. sylvestris. 



520. M. Alcea L. (Herm, Miiller, 'Fertilisation,' p. 144, 'Weiu Beob.,' II, 

 p. 221 ; Warnstorf, Verh. bot. Ver., Berlin, xxxviii, 1896.) As No. 519. 



